Bug Description

The purpose of this patch is to allow a hub bot to recieve the magnet link to a file. An example use is for a release bot, as follows:
1. The user adds a new file to their share.
2. The user opens their file list, right clicks on the file, and selects User Commands>Add Release.
3. The client passes the magnet link to the release bot via the fileMN key.
4. The release bot takes the magnet link and adds it to the list of releases.

I believe the patch will produce a valid, correctly escaped magnet, but somebody checking that it does would be nice.